In a Coq8a−/− constitutive knockout mouse model of autosomal recessive ataxia type 2 with progressive cerebellar ataxia, exercise intolerance, and memory impairment, mitochondria seem to belong to culprits of the whole pathological process: Purkinje neurons display altered expression of respiratory complexes, in particular complex IV, at presymptomatic stages of the disease [59]. This evidence concerns the gene COQ8A and cerebellar ataxia.